Cardiac resynchronization therapy for heart failure induced by left bundle branch block after transcatheter closure of ventricular septal defect

A 54-year-old female patient with congenital heart disease had a persistent complete left bundle branch block three months after closure by an Amplatzer ventricular septal defect occluder. Nine months later, the patient suffered from chest distress, palpitation, and sweating at daily activities, and her 6-min walk distance decreased significantly （155 m）. Her echocardiography showed increased left ventricular end-diastolic diameter with left ventricular ejection fraction of 37%. Her symptoms reduced significantly one week after received cardiac resynchronization therapy. She had no symptoms at daily activities, and her echo showed left ventricular ejection fraction of 46%and 53%. Moreover, left ventricular end-diastolic diameter decreased 6 and 10 months after cardiac resynchronization therapy, and 6-min walk dis-tance remarkably increased. This case demonstrated that persistent complete left bundle branch block for nine months after transcatheter closure with ventricular septal defect Amplatzer occluder could lead to left ventricular enlargement and a significant decrease in left ventricular systolic function. Cardiac resynchronization therapy decreased left ventricular end-diastolic diameter and increased left ventricular ejection fraction, thereby improving the patient’s heart functions.

Delayed spontaneous reversibility of left bundle branch block in non-ischemic cardiomyopathy: a case report

Left bundle branch block(LBBB)causes a delay in left ventricular contraction with an unsynchronized ventricular systole.LBBB is an independent determinant of morbi-mortality mainly when associated with cardiomyopathy and left ventricular dysfunction.[1] LBBB due to non-ischemic cardiomyopathy is considered non-reversible.Such irreversibility occurs because LBBB and cardiomyopathy act in a synergic manner in order to maintain both situations.However,there are a few reports in the literature showing that some patients have had an improvement in cardiac function with normalization of QRS and have experienced a reverse remodelling with pharmacological therapy only.[2–4]

Left bundle branch pacing set to outshine biventricular pacing for cardiac resynchronization therapy?

The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacinginduced cardiomyopathy.Until recently,biventricular pacing(BiVP)was the only modality which could mitigate or prevent pacing induced dysfunction.Further,BiVP could resynchronize the baseline electromechanical dssynchrony in heart failure and improve outcomes.However,the high non-response rate of around 20%-30%remains a major limitation.This non-response has been largely attributable to the direct non-physiological stimulation of the left ventricular myocardium bypassing the conduction system.To overcome this limitation,the concept of conduction system pacing(CSP)came up.Despite initial success of the first CSP via His bundle pacing(HBP),certain drawbacks including lead instability and dislodgements,steep learning curve and rapid battery depletion on many occasions prevented its widespread use for cardiac resynchronization therapy(CRT).Subsequently,CSP via left bundle branch-area pacing(LBBP)was developed in 2018,which over the last few years has shown efficacy comparable to BiVP-CRT in small observational studies.Further,its safety has also been well established and is largely free of the pitfalls of the HBP-CRT.In the recent metanalysis by Yasmin et al,comprising of 6 studies with 389 participants,LBBPCRT was superior to BiVP-CRT in terms of QRS duration,left ventricular ejection fraction,cardiac chamber dimensions,lead thresholds,and functional status amongst heart failure patients with left bundle branch block.However,there are important limitations of the study including the small overall numbers,inclusion of only a single small randomized controlled trial(RCT)and a small follow-up duration.Further,the entire study population analyzed was from China which makes generalizability a concern.Despite the concerns,the meta-analysis adds to the growing body of evidence demonstrating the efficacy of LBBP-CRT.At this stage,one must acknowledge that the fact that still our opinions on this technique are largely based on observational data and there is a dire need for larger RCTs to ascertain the position of LBBPCRT in management of heart failure patients with left bundle branch block.

Defective T wave combined with incomplete right bundle branch block： a new electrocardiographic index for diagnosing atrial septal defect

Background Incomplete right bundle branch block （ICRBBB） is commonly associated with atrial septal defect （ASD）, but lacks sufficient diagnostic test characteristics. An abnormal T wave is also often observed in ASD, with horizontal or inverted displacement of the proximal T wave limb in the right precordial leads, termed ＂defective T wave＂ （DTW）. Methods We examined the diagnostic test characteristics of combining ICRBBB with DTW as a new index to diagnose ASD. A total of 132 consecutive patients with ASD and 132 cases of age/gender-matched controls without ASD were enrolled. Results Sensitivities of DTW, ICRBBB, and both were 87.1%-87.9%. Specificities were 97.0%, 96.2%, and 100%, respectively. Positive predictive values were 1.3%, 1.1%, and 100.0% respectively, while negative predictive values were 99.9% for each. Conclusion Combining ICRBBB with DTW in electrocardiogram （ECG） as a new index significantly increased the specificity and positive predictive values while maintaining a high sensitivity in diagnosing ASD.

Assessment of cardiac function and synchronicity in subjects with isolated bundle branch block using Doppler imaging

Background Using tissue Doppler imaging and conventional echocardiographic technique, we examined the cardiac function and synchronicity in individuals with isolated right bundle branch block （RBBB） or left bundle branch block （LBBB） and assessed the relationship between QRS duration and synchronicity.

Clinical efficacy and predictor of cardiac resynchronization therapy on left bundle branch block-associated heart dysfunction

Background Left bundle branch block （LBBB） results in an altered pattern of left ventricular （LV） activation and subsequent contraction. Cardiac synchrony and cardiac function are deteriorated by LBBB. However, the effect of LBBB history on progressive heart dysfunction and clinical efficacy of cardiac resynchronization therapy （CRT） in such patients are not clear. In this study we explore the clinical efficacy and predictor of cardiac resynchronization therapy in LBBB heart dysfunction. Methods Twenty-seven LBBB patients with severe heart failure were treated with CRT. Twenty-six LBBB patients without CRT served as control. During 6 months follow-up, ECG, plasma NT-proBNP and echocardiogram indexes were measured. Results Compared with baseline, NYHA functional class of 23 patients （85.2%） was improved in CRT group. Compared with baseline and control, QRS duration （QRSd） was significantly more narrow （P = 0.023, P = 0.019）, NT-proBNP was significantly lower （P = 0.011,P = 0.009）, ventricular septal to left ventricular posterior wall delay time and left ventricular dyssynchrony index （Ts-SD） were significantly worse （P 〈 0.05）; left ventricular ejection fraction, left ventricular end-systolic volume, mitral regurgitation area were significantly improved in CRT group （P 〈 0.05）. when the LBBB history was I〉 2 years and QRSd I〉 155 ms, the sensitivity and specificity of CRT super-response were 53.4% and 85.6% respectively. Conclusions CRT can improve the synchronization and hemodynamic of LBBB patients with heart dysfunction, the LBBB history I〉 2 years and QRSd I〉 155 ms are one of the CRT super-response predictors.

Cardioprotective effects of trimetazidine on patients with dilated cardiomyopathy and left bundle branch block

Background The effects of trimetazidine on patients with dilated cardiomyopathy（DCM） and left bundle branch block（LBBB） are not clear. Methods Sixty consecutive patients with DCM, LBBB and heart dysfunction（35% ≤ LVEF ≤ 45%） were randomly allocated to heart failure therapy plus trimetazidine group（20 mg three times a day; 30 patients） or heart failure therapy alone group（30 patients）. During follow-up of 6months, QRS morphology, plasma NT-proBNP, 6-minute walk test（6MWT） and echocardiographic indexes were measured. Results At the 6th month, a significant functional improvement was noted in patients receiving trimetazidine added to heart failure treatment. In patients from the trimetazidine group, an increase of left ventricular ejection fraction（LVEF） was noted（from 38 ± 5.5% to 47 ± 7.1%, P = 0.020）. The increase of LVEF in the trimetazidine group was associated with a more significant reduction of the left ventricular endsystolic diameter（LVESD） compared with the control group at 6-month follow-up. The NT-pro BNP levels decreased significantly in the trimetazidine group（3.11 ± 0.47 at baseline and 2.77 ± 0.45 at 6-month followup, P 〈 0.01） and the 6MWT increased significantly in the trimetazidine group（325 ± 44 m at baseline and419 ± 56 m at 6-month follow-up, P 〈 0.01）. The differences in NT-pro BNP levels（2.77 ± 0.45 vs 2.96 ±0.46, P = 0.036） and 6MWT（419 ± 56 m vs 366 ± 54 m, P = 0.032） between the two groups were significant at 6-month follow-up. Conclusions Trimetazidine can improve LV function caused by DCM and LBBB. The positive effects of trimetazidine on LV function are especially evident in patients with optimization of drug therapy for heart failure, which strongly suggests an additive effect of these therapy modalities.

Intermittent Left Bundle Branch Block and Myocardial Ischemia in Patient Without Coronary Artery Stenosis:A Case Report

Left bundle branch block （ LBBB ）, traditionally viewed as an electrophysiologic abnormality, is increasingly recognized for its effects on hemodynamics and patient＇s prognosis^[1]. Exercise nuclear studies frequently show reversible perfusion defects in the absence of obstructive coronary artery disease^[2] and some patients with intermittent LBBB develop angina coincident with the onset of LBBB^[3]. We report a case of intermittent LBBB with abnormal stress technetium 99m TC single-photon emission computed tomography （SPECT） study and normal coronary artery angiography.

Outcomes in patients with COVID-19 and new onset heart blocks: Insight from the National Inpatient Sample database

BACKGROUND Coronavirus disease 2019(COVID-19)caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has resulted in a worldwide health crisis since it first appeared.Numerous studies demonstrated the virus’s predilection to cardiomyocytes;however,the effects that COVID-19 has on the cardiac conduc-tion system still need to be fully understood.AIM To analyze the impact that COVID-19 has on the odds of major cardiovascular complications in patients with new onset heart blocks or bundle branch blocks(BBB).METHODS The 2020 National Inpatient Sample(NIS)database was used to identify patients admitted for COVID-19 pneumonia with and without high-degree atrioven-tricular blocks(HDAVB)and right or left BBB utilizing ICD-10 codes.The patients with pre-existing pacemakers,suggestive of a prior diagnosis of HDAVB or BBB,were excluded from the study.The primary outcome was inpatient mortality.Secondary outcomes included total hospital charges(THC),the length of hospital stay(LOS),and other major cardiac outcomes detailed in the Results section.Univariate and multivariate regression analyses were used to adjust for confounders with Stata version 17.RESULTS A total of 1058815 COVID-19 hospitalizations were identified within the 2020 NIS database,of which 3210(0.4%)and 17365(1.6%)patients were newly diagnosed with HDAVB and BBB,respectively.We observed a significantly higher odds of in-hospital mortality,cardiac arrest,cardiogenic shock,sepsis,arrythmias,and acute kidney injury in the COVID-19 and HDAVB group.There was no statistically significant difference in the odds of cerebral infarction or pulmonary embolism.Encounters with COVID-19 pneumonia and newly diagnosed BBB had a higher odds of arrythmias,acute kidney injury,sepsis,need for mechanical ventilation,and cardiogenic shock than those without BBB.However,unlike HDAVB,COVID-19 pneumonia and BBB had no significant impact on mortality compared to patients without BBB.CONCLUSION In conclusion,there is a significantly higher odds of inpatient mortality,cardiac arrest,cardiogenic shock,sepsis,acute kidney injury,supraventricular tachycardia,ventricular tachycardia,THC,and LOS in patients with COVID-19 pneumonia and HDAVB as compared to patients without HDAVB.Likewise,patients with COVID-19 pneumonia in the BBB group similarly have a higher odds of supraventricular tachycardia,atrial fibrillation,atrial flutter,ventricular tachycardia,acute kidney injury,sepsis,need for mechanical ventilation,and cardiogenic shock as compared to those without BBB.Therefore,it is essential for healthcare providers to be aware of the possible worse predicted outcomes that patients with new-onset HDAVB or BBB may experience following SARS-CoV-2 infection.

Pacemaker post transcatheter aortic valve replacement:A multifactorial risk?

Pacemaker post-transcatheter aortic valve replacement is related to multifactorial risk.Nwaedozie et al brought to the body of evidence electrocardiogram and clinical findings.However,procedural characteristics have at least as much impact on the final need for a permanent pacemaker and potentially on the pacing rate.In this regard,long-term follow-up and understanding of the impact of long-term stimulation is of utmost importance.

Predictors of permanent pacemaker implantation following transcatheter aortic valve replacement-the search is still on!

Several anatomical,demographic,clinical,electrocardiographic,procedural,and valve-related variables can be used to predict the probability of developing con-duction abnormalities after transcatheter aortic valve replacement(TAVR)that necessitate permanent pacemaker(PPM)implantation.These variables include calcifications around the device landing zone and in the mitral annulus;pre-existing electrocardiographic abnormalities such as left and right bundle branch blocks(BBB),first-and second-degree atrioventricular blocks,as well as bifas-cicular and trifascicular blocks;male sex;diabetes mellitus(DM);hypertension;history of atrial fibrillation;renal failure;dementia;and use of self-expanding valves.The current study supports existing literature by demonstrating that type 2 DM and baseline right BBB are significant predictors of PPM implantation post-TAVR.Regardless of the side of the BBB,this study demonstrated,for the first time,a linear association between the incidence of PPM implantation post-TAVR and every 20 ms increase in baseline QRS duration(above 100 ms).After a 1-year follow-up,patients who received PPM post-TAVR had a higher rate of hospital-ization for heart failure and nonfatal myocardial infarction.

Comparison of His-purkinje bundle pacing and right ventricular inflow tract septal pacing in the elderly

Objective To compare the short-term clinical effect and electrical parameters of His-purkinje bundle pacing(HPBP) and right ventricular inflow tract septal pacing(RVIP) in the elderly. Methods Between April 2017 and September 2019, sixty patients with indications for permanent cardiac pacing and resynchronization therapy in Beijing Anzhen Hospital were divided into the HPBP and RVIP groups, and were analyzed. A ventricular pacing lead was implanted in left ventricular septal sites with left bundle potentials or His potentials in the HPBP group. The lead was placed in right ventricular inflow tract septal sites close to distal His-bundle regions without potentials from the His-purkinje conduction system in the RVIP group. Lead impedance, R wave amplitude, pacing thresholds, QRS duration, left ventricular ejection fraction(LVEF), and left ventricular end-diastolic diameter(LVEDD), mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio were compared between the HPBP and RVIP groups during the procedure and the short-month follow-up. Results No significant differences were found in lead impedance, R wave amplitude, QRS duration, LVEF, LVEDD, mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio between the HPBP and RVIP groups. However, the pacing threshold was significantly lower in the HPBP group than in the RVIP group(0.7 ± 0.2 vs. 0.9 ± 0.3 V, P = 0.02). Conclusions The efficacy and electrical parameters of HPBP is comparable with RVIP during the procedure and the short-term follow-up.

Inadvertent Lead Malposition in the Left Ventricle during Permanent Ventricular Pacing about One Case

Inadvertent Lead Malposition in Left Ventricle is a rare and underdiagnosed incident, which may occur during implantation of cardiac electronic devices and may remain asymptomatic. We reported the case of a 71-year-old man who was implanted with a ventricular single-chamber pacemaker for a slow atrial fibrillation with syncope and whose routine transthoracic echocardiography 23 months after implantation displayed a malposition of the pacemaker lead into the Left Ventricle through a patent foramen oval. The patient was asymptomatic. The electrocardiogram showed right bundle branch block QRS-paced morphology with a positive QRS pattern in V1, a median paced QRS axis on the frontal plane at -120°, a Precordial transition on V5. At the lateral Chest X-ray the lead curved backwards to the spine. Given the age of this old patient who already received oral anticoagulant for Atrial Fibrillation and the Lead malposition discovered 23 months after pacemaker’s implantation, we decided to maintain the lead in LV and continue anticoagulation.

Defective recovery of QT dispersion following transcatheter aortic valve implantation： frequency, predictors and prognosis

Background Corrected QT dispersion （cQTD） has been correlated with non-uniform ventricular repolarisation and increased mortality. In patients with aortic stenosis, cQTD has been shown improved after surgical valve replacement, but the effects of transcatheter aortic valve implantation （TAVI） are unknown. Therefore, we sought to explore the frequency, predictors and prognostic effects of defective cQTD recovery at 6 months after TAVI. Methods A total of 222 patients underwent TAVI with the Medtronic-CoreValve System between November 2005 and January 2012. Patients who were on class Ⅰ or Ⅲ antiarrhythmics or on chronic haemodialysis or who developed atrial fibrillation, a new bundle branch block or became pacemaker dependent after TAVI were excluded. As a result, pre-, post- and follow-up ECG （median： 6 months） analysis was available in 45 eligible patients. Defective cQTD recovery was defined as any progression beyond the baseline cQTD at 6 months. Results In the 45 patients, the mean cQTD was 47 ± 23 ms at baseline, 45 ±17 ms immediately after TAVI and 40 ± 16 ms at 6 months （15% reduction, P = 0.049）. Compared to baseline, cQTD at 6 months was improved in 60% of the patients whereas defective cQTD recovery was present in 40%. cQTD increase immediately after TAVI was an independent predictor of defective cQTD recovery at 6 months （per 10 ms increase; OR： 1.89, 95% CI： 1.15-3.12）. By univariable analysis, defective cQTD recovery was associated with late mortality （HR： 1.52, 95% CI： 1.05-2.17）. Conclusions Despite a gradual reduction ofcQTD after TAVI, 40% of the patients had defective recovery at 6 months which was associated with late mortality. More detailed ECG analysis after TAVI may help to avoid late death.

Cardiac resynchronization therapy: Dire need for targeted left ventricular lead placement and optimal device programming

Cardiac resynchronization therapy(CRT) effected via biventricular pacing has been established as prime therapy for heart failure patients of New York Heart Association functional class Ⅱ, Ⅲ and ambulatory Ⅳ, reduced left ventricular(LV) function, and a widened QRS complex. CRT has been shown to improve symptoms, LV function, hospitalization rates, and survival. In order to maximize the benefit from CRT and reduce the number of non-responders, consideration should be given to target the optimal site for LV lead implantation away from myocardial scar and close to the latest LV site activation; and also to appropriately program the device paying particular attention to optimal atrioventricular and interventricular intervals. We herein review current data related to both optimal LV lead placement and device programming and their effects on CRT clinical outcomes.

Review of Computational Techniques for the Analysis of Abnormal Patterns of ECG Signal Provoked by Cardiac Disease

The 12-lead ECG aids in the diagnosis of myocardial infarction and is helpful in the prediction of cardiovascular disease complications.It does,though,have certain drawbacks.For other electrocardiographic anomalies such as Left Bundle Branch Block and Left Ventricular Hypertrophy syndrome,the ECG signal withMyocardial Infarction is difficult to interpret.These diseases cause variations in the ST portion of the ECG signal.It reduces the clarity of ECG signals,making itmore difficult to diagnose these diseases.As a result,the specialist is misled into making an erroneous diagnosis by using the incorrect therapeutic technique.Based on these concepts,this article reviews the different procedures involved in ECG signal pre-processing,feature extraction,feature selection,and classification techniques to diagnose heart disorders such as LeftVentricularHypertrophy,Bundle Branch Block,andMyocardial Infarction.It reveals the flaws and benefits in each segment,as well as recommendations for developing more advanced and robustmethods for diagnosing these diseases,which will increase the system’s accuracy.The current issues and prospective research directions are also addressed.

Conduction abnormalities after transcatheter aortic valve implantation

In the last few years, transcatheter aortic valve implantation （TAVI） has become an alternative procedure in patients with severe aortic stenosis and high risk for surgical aortic replacement. Due to the anatomic correlation between aortic valve structure and conduction system of the heart, one of the most common complications after TAVI is conduction system disturbances which including bundle branch block, complete heart block and need for permanent pacemaker implantation. Although these disturbances are usually not lethal, they may have a great influence on patients＇ state and long term-survival. Several risk factors for conduction disturbances have been identified which including age, anatomy of the heart, periprocedural factors, type of implanted valve, preexisting abnormalities and comorbidities. As this technique becomes more familiar to physicians, patients should be carefully screened for risk factors for the development of conduction abnormalities after TAVI in order to provide effective prevention and proper treatment.

A Healthcare System for Internet of Things (IoT) Application: Machine Learning Based Approach

Internet of things (IoT) has become an interesting topic in the field of technological research. It is basically interconnecting of devices with each other over the internet. Beside its general use in terms of autonomous cars and smart homes, but some of the best applications of IoT technology in fields of health care monitoring is worth mentioning. The main purpose of this research work is to provide comport services for patients. It can be used to promote basic nursing care by improving the quality of care and patient safety from patient home environment. Rural area of a country lacks behind the proper patient monitoring system. So, remote monitoring and prescribing by sharing medical information in an authenticated manner is very effective for betterment of medical facilities in rural area. We have proposed a healthcare system which can analyze ECG report using supervise machine learning techniques. Analyzing report can be stored in cloud platform which can be further used to prescribe by the experienced medical practitioner. For performance evaluation, ECG data is analyzed using six supervised machine learning algorithms. Data sets are divided into two groups: 75 percent data for training the model and rest 25 percent data for testing. To avoid any kind of anomalies or repetitions, cross validation and random train-test split was used to obtain the result as accurate as possible.

Clinical Characteristics and Prognosis of End-stage Hypertrophic Cardiomyopathy

Background： End-stage hypertrophic cardiomyopathy （HCM） is complicated by substantial adverse events. However, few studies have focused on electrocardiographic features and their prognostic values in HCM. This study aimed to evaluate the clinical manifestations and prognostic value of electrocardiography in patients with end-stage HCM. Methods： End-stage HCM patients were enrolled from a total of 1844 consecutive HCM patients from April 2002 to November 2013 at Fuwai Hospital. Clinical data, including medical history, electrocardiography, and echocardiography, were analyzed. Cox hazards regression analysis was used to assess the risk factors for cardiovascular mortality. Results： End-stage HCM was identified in 99 （5.4%） patients, averaged at 52 ± 16 years old at entry. Atrial fibrillation was observed in 53 patients and mural thrombus in 19 patients. During 3.9 ±3.0 years of follow-up, embolic stroke, refractory heart failure, and death or transplantation were observed in 20, 39, and 51 patients, respectively. The incidence of annual mortality was 13.2%. Multivariate Cox hazards regression analysis identified New York Heart Association Class （NYHA） Ill/IV at entry （hazard ratio [HR]： 1.99; 95% confidence interval [C/I： 1.05-3.80; P = 0.036）, left bundle branch block （LBBB） （HR： 2.80; 95% CI： 1.47-5.31; P = 0.002）, and an abnormal Q wave （HR： 2.21; 95% CI： 1.16-4.23; P = 0.016） as independent predictors of cardiovascular death, in accordance with all-cause death and heart failure-related death. Conclusions： LBBB and an abnormal Q wave are risk factors of cardiovascular mortality in end-stage HCM and provide new evidence for early intervention. Susceptibility of end-stage HCM patients to mural thrombus and embolic events warrants further attention.

Electrocardiographic findings in leads V_(3R) to V_(5R) in patients with a slurred or notched S wave in lead V_1

Background Right bundle branch block （RBBB） may present as slurred or notched S wave in lead V1. However, slurred or notched S wave may also represent slow conduction in the myocardium. Methods We retrospectively analyzed the QRS patterns in leads VgR to V5R in 7 patients with a slurred or notched S wave in lead V1. Results In the leads V3R to VSR, 6 patients showed incomplete or complete RBBB and 1 patient slurred or notched S wave. Conclusions In the majority of ECGs in a small patient series with slurred or notched S wave in lead V1, QRS morphology indicating incomplete or complete RBBB was present in leads V3R to VSR. A finding of fragmented QRS in these leads may indicate slow conduction in the myocardium.